<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<script>
    var sum = 0;
    for(var i = 0;i <= 100;i++){
        if(i % 3 ==0){
            sum += i;
        }
    }
    alert('能被3整数的数字的和'+sum);
</script>
<body>

</body>
</html>